Heat olive oil in a medium skillet over medium heat. Add the chopped onion and cook until softened, about 2 minutes. Then add the minced garlic and red pepper flakes; stir for about 1 minute until fragrant.

Stir in the mashed tomatoes along with their juice. Season with dried oregano, salt, and pepper, and let the sauce simmer for about 10 minutes until it thickens slightly. If it becomes too thick, add up to 1/2 cup water to thin it.

Stir in the torn basil near the end of simmering. Adjust seasonings as needed.

Make 4 small wells in the sauce with the back of a spoon. Carefully crack one egg into each well. Sprinkle 1 tablespoon of grated Parmesan cheese evenly over the eggs.

Cover the skillet and cook for about 5 minutes until the egg whites are set but the yolks remain runny.

Remove the skillet from heat. Sprinkle the remaining Parmesan cheese over the dish and add extra basil if desired. Serve immediately with toasted bread.